The present invention relates to, in a recording apparatus such as a printer, a motor control method in a recording apparatus which serves to accurately estimate the heat generation of an electric motor without using a temperature sensor and to carry out control for limiting the heat generation of the electric motor based on information about the heat generation thus estimated, and the recording apparatus.
In a serial printer, conventionally, a carriage including a print head runs in a main scanning direction (an orthogonal direction to a paper feeding direction) so that printing is carried out over a print medium such as a paper, for example. The carriage is driven to run by a carriage motor provided in the printer. An electric motor such as a DC motor is used for the carriage motor, for example.
The electric motor such as the carriage motor generates heat corresponding to a power consumed by driving. Since the electric motor is designed to be used at a standard temperature, it is used at the standard temperature or less in an ordinary printing operation.
However, in the case in which an excessive load is applied to the electric motor because the electric motor is driven at a high speed or an excessive sliding resistance is applied during the movement of the carriage, the temperature of the electric motor may exceed the standard temperature. In this case, there has been known heat generating limitation control to take a pause having a predetermined time such that the electric motor can be prevented from breaking down by heat.
Usually, the temperature of the motor is detected by using a temperature sensor. There is supposed that a pause having a predetermined time is taken to carry out heat generating limitation control for limiting heat generation when the temperature of the motor is higher than the standard temperature.
However, there is a problem in that the number of components is increased by using the temperature sensor, resulting in an increase in a manufacturing cost.
The invention has been made to solve the problems and has a first object to provide a motor control method in a recording apparatus in which the temperature of the heat generation of an electric motor can be estimated comparatively accurately in consideration of a radiation with the passage of time without using a temperature sensor and control for limiting the heat generation of the electric motor can be carried out suitably, and the recording apparatus.
In order to attain the first object, the invention has a second object to estimate the temperature of the heat generation of an electric motor comparatively accurately in consideration of a radiation, thereby reducing a useless pause for the electric motor to enhance the throughput of the recording apparatus.
The invention has a third object to estimate the temperature of the heat generation of the electric motor comparatively accurately in consideration of the radiation with the passage of time without using a temperature sensor.
The invention has a fourth object to estimate the temperature of the heat generation of the electric motor comparatively accurately in consideration of the radiation with the passage of time without using the temperature sensor, thereby deciding the abnormality of the heat generation of the electric motor comparatively accurately.
(1) In order to achieve the first and second objects, the invention is directed to a motor control method in a recording apparatus comprising an electric motor to be driven based on a power supplied from power supply means, comprising the steps of successively obtaining a value related to a heat value based on a consumed current and a driving time of the electric motor, successively obtaining a value related to a heat storage amount of the electric motor in consideration of a radiation by using the value related to the heat value, and controlling the electric motor to take a pause at an interval of a driving operation thereof based on the value related to the heat storage amount.
According to the invention, the value related to the heat value is obtained based on the consumed current and the driving time of the electric motor, and furthermore, the value related to the heat storage amount of the electric motor is successively obtained in consideration of the radiation by using the value related to the heat value and the electric motor is controlled to take a pause at the interval of the driving operation thereof based on the value related to the heat storage amount. The heat generation temperature of the electric motor is estimated comparatively accurately based on the value related to the heat storage amount. Consequently, the unnecessary pause of the electric motor can be decreased.
(2) In order to achieve the first and second objects, the invention is directed to a motor control apparatus in a recording apparatus comprising an electric motor to be driven based on a power supplied from power supply means, comprising heat value acquiring means for successively obtaining a value related to a heat value based on a consumed current and a driving time of the electric motor, heat storage amount acquiring means for successively obtaining a value related to a heat storage amount of the electric motor in consideration of a radiation by using the value related to the heat value, and pause control means for controlling the electric motor to take a pause at an interval of a driving operation thereof based on the value related to the heat storage amount.
According to the invention, by the same functions of the invention described in (1), the heat generation temperature of the electric motor is estimated comparatively accurately based on the value related to the heat storage amount in consideration of the radiation. Consequently, the unnecessary pause of the electric motor can be decreased.
(3) In order to achieve the first and second objects, the invention is directed to a motor control apparatus in a recording apparatus comprising an electric motor to be driven based on a power supplied from power supply means, comprising heat value acquiring means for successively obtaining a value related to a heat value based on a consumed current and a driving time of the electric motor, heat storage amount acquiring means for obtaining a value related to a last heat storage amount in consideration of a radiation by using the value related to the heat value and for adding a value related to a heat value obtained next time by the heat value acquiring means to the value related to the last heat storage amount, thereby obtaining a value related to a present heat storage amount, and pause control means for controlling the electric motor to take a pause at an interval of a driving operation thereof based on the value related to the present heat storage amount.
According to the invention, the value related to the heat value is obtained based on the consumed current and the driving time of the electric motor, the value related to the last heat storage amount is obtained in consideration of the radiation by using the value related to the heat value, and the value related to the heat value obtained next time is added to the value related to the last heat storage amount so that the value related to the present heat storage amount is obtained. The electric motor is controlled to take a pause at the interval of the driving operation thereof based on the value related to the present heat storage amount.
(4) In order to achieve the first and second objects, the invention is directed to a motor control apparatus in a recording apparatus comprising an electric motor to be driven based on a power supplied from power supply means, comprising heat value acquiring means for obtaining a heat value based on a consumed current and a driving time of the electric motor, adding means for obtaining an added value of the heat value with a correcting operation in consideration of a radiation with the passage of time, and pause control means for controlling the electric motor to take a pause at an interval of a driving operation thereof when the added value exceeds a predetermined threshold.
According to the invention, the heat value is obtained based on the consumed current and the driving time of the electric motor and the added value of the heat value is obtained with the correcting operation in consideration of the radiation with the passage of time. When the added value exceeds the predetermined threshold, the electric motor is controlled to take a pause at the interval of the driving operation thereof.
(5) In order to achieve the first and second objects, the invention is directed to a motor control apparatus in a recording apparatus comprising an electric motor to be driven based on a power supplied from power supply means, comprising heat generation temperature estimating means for obtaining a value related to a heat value based on a consumed current and a driving time of the electric motor and for adding the value related to the heat value with a correcting operation in consideration of a radiation, thereby estimating a value related to a heat generation temperature of the electric motor based on the added value, the electric motor being controlled to take a pause at an interval of a driving operation when the value related to the heat generation temperature exceeds a predetermined threshold.
According to the invention, the value related to the heat value is obtained based on the consumed current and the driving time of the electric motor, the value related to the heat value is added with the correcting operation in consideration of the radiation, and the value related to the heat generation temperature of the electric motor is estimated based on the added value. When the value related to the heat generation temperature exceeds a predetermined threshold, the electric motor is controlled to take a pause at the interval of the driving operation.
(6) In order to achieve the first and second objects, the invention is directed to the recording apparatus according to any of (3) to (5), wherein a plurality of predetermined thresholds are provided, and when a corresponding one of the value related to the heat storage amount, the added value and the heat generation temperature estimated value exceeds at least one of the thresholds, the pause control means controls the electric motor to take a pause for a pause time corresponding to the exceeded threshold at an interval of a driving operation of the electric motor.
According to the invention, in the invention described in any of claims (3) to (5), a corresponding one of the value related to the heat storage amount, the added value and the heat generation temperature estimated value exceeds at least one of the thresholds, the electric motor is controlled to take a pause for a pause time corresponding to the exceeded threshold at an interval of a driving operation of the electric motor.
(7) In order to achieve the first and second objects, the invention is directed to a serial type recording apparatus in which a carriage having a recording head is reciprocated in a main scanning direction, thereby carrying out recording over a recording medium by the recording head, comprising an electric motor to be driven for reciprocating the carriage in the main scanning direction, heat value acquiring means for calculating a heat value per unit time based on a consumed current and a driving time of the electric motor, and pause control means for successively adding the heat value per unit time with a correcting operation in consideration of a radiation with the passage of time to obtain an added value and for controlling the electric motor to take a pause time during an inversion of a movement of the carriage when the added value exceeds a predetermined threshold.
According to the invention, the heat value per unit time is calculated by the heat value acquiring means based on the consumed current and the driving time of the electric motor, and the heat value per unit time is successively added with the correcting operation in consideration of the radiation with the passage of time to obtain the added value and the electric motor is controlled by the pause control means to take a pause time at time of the inversion of the movement of the carriage when the added value exceeds the predetermined threshold. In the serial type recording apparatus, accordingly, the heat generation of the electric motor is estimated comparatively accurately based on the added value of the heat value in consideration of the radiation with the passage of time. Consequently, the unnecessary pause of the electric motor can be decreased.
(8) In order to achieve the first and second objects, the invention is directed to a serial type recording apparatus in which a carriage having a recording head is reciprocated in a main scanning direction, thereby carrying out recording over a recording medium by the recording head, comprising an electric motor to be driven for reciprocating the carriage in the main scanning direction, unit heat value acquiring means for calculating a unit heat value per pass of the carriage based on a consumed current and a driving time of the electric motor, heat value acquiring means for successively adding the unit heat value and obtaining a heat value per unit time, and pause control means for successively adding the heat value per unit time with a correcting operation in consideration of a radiation with the passage of time to obtain an added value and for controlling the electric motor to take a pause time at an interval between passes of the carriage when the added value exceeds a predetermined threshold.
According to the invention, the unit heat value per pass of the carriage is obtained by the unit heat value acquiring means based on the consumed current and the driving time of the electric motor, and the unit heat value is successively added to obtain the heat value per unit time by the heat value acquiring means. Then, the heat value per unit time is successively added with the correcting operation in consideration of the radiation with the passage of time to obtain an added value, and furthermore, the electric motor is controlled by the pause control means to take a pause time at the interval between the passes of the carriage when the added value exceeds a predetermined threshold. In the serial type recording apparatus, accordingly, the heat generation of the electric motor is estimated comparatively accurately based on the added value of the heat value in consideration of the radiation with the passage of time. Consequently, the unnecessary pause of the electric motor can be decreased.
(9) In order to achieve the first and second objects, the invention is directed to the recording apparatus according to any of (2) to (8), the electric motor has a speed controlled to move a moving member by one driving through speed setting in which an acceleration and deceleration area and a constant speed area are set, and includes a memory for dividing a consumed current per driving of the electric motor into a load current value depending on a load applied to the electric motor when moving the moving member and a fixed current value corresponding to an inertia portion when accelerating and decelerating the moving member and for storing the fixed current value which is previously obtained, current measuring means for measuring a current in the constant speed area, thereby obtaining a current measured value, and calculating means for calculating a consumed current value per driving by using a load current value determined based on the current measured value in the constant speed area and the fixed current value stored in the memory, the heat value acquiring means obtaining a value related to the heat value by using the consumed current value per driving.
According to the invention, in addition to the functions of the invention in accordance with any of (2) to (8), the speed of the electric motor is controlled to move a moving member by one driving through speed setting in which the acceleration and deceleration area and the constant speed area are set. The consumed current value per driving of the electric motor is divided into the load current value depending on the load applied to the electric motor when moving the moving member and the fixed current value corresponding to the inertia portion when accelerating and decelerating the moving member. The fixed current value obtained previously is stored in the memory. The current in the constant speed area is measured by the current measuring means to obtain the current measured value, thereby determining the load current value based on the current measured value in the constant speed area. Then, the consumed current value per driving is calculated by the operation means with the use of the load current value and the fixed current value stored in the memory. By using the consumed current value and the driving time per driving, the value related to the heat value per driving is obtained.
(10) In the recording apparatus described in (7) or (8) of the invention, the pause control means sets a pause time corresponding to the moving speed and the moving distance of the carriage to have an effective current value per pass of the carriage to be almost equal.
According to the invention, in addition to the functions of the invention (7) or (8), the pause time corresponding to the moving speed and the moving distance of the carriage is set such that the effective current value per pass of the carriage is almost equal by the pause control means. Accordingly, the degree of the limitation of the heat generation in the electric motor is almost equal between the passes in which the moving speed and the moving distance of the carriage are varied. Thus, a stable heat generating limitation can be carried out.
(11) In the recording apparatus according to any of the inventions (2) to (10), the pause control means continuously carries out the heat generating limitation control for limiting the heat generation of the electric motor with the pause time until the added value is decreased to the release threshold which is set to be smaller than the predetermined threshold.
According to the invention, in addition to the functions in accordance with any of the inventions (2) to (10), the heat generating limitation control for limiting the heat generation of the electric motor is continuously carried out with a pause time until the added value is decreased to the release threshold set to be smaller than the predetermined threshold. Accordingly, it is possible to reliably separate the heat generation temperature of the electric motor from an overheat state.
(12) In order to achieve the third object, the invention is directed to a serial type recording apparatus in which a carriage having a recording head is reciprocated in a main scanning direction, thereby carrying out recording over a recording medium by the recording head, comprising an electric motor to be driven for reciprocating the carriage in the main scanning direction, heat value acquiring means for calculating a heat value per unit time based on a consumed current and a driving time of the electric motor, and temperature estimating means for successively adding the heat value per unit time with a correcting operation in consideration of a radiation with the passage of time to obtain an added value and for estimating a heat generation temperature of the electric motor based on the added value.
According to the invention, the heat value per unit time is calculated by the heat value acquiring means based on the consumed current and the driving time of the electric motor. The temperature estimating means sequentially adds the heat value per unit time with the correcting operation in consideration of the radiation with the passage of time to obtain an added value, and furthermore, estimates the heat generation temperature of the electric motor based on the added value. Accordingly, it is possible to estimate the heat generation temperature of the electric motor comparatively accurately. For example, a pause is taken to the interval of the driving operation of the electric motor. Thus, it is possible to suitably carry out the heat generating limitation control to reduce the effective current value.
(13) In order to achieve the third object, the invention is directed to a serial type recording apparatus in which a carriage having a recording head is reciprocated in a main scanning direction, thereby carrying out recording over a recording medium by the recording head, comprising an electric motor to be driven for reciprocating the carriage in the main scanning direction, unit heat value acquiring means for calculating a unit heat value per pass of the carriage based on a consumed current and a driving time of the electric motor, heat value acquiring means for successively adding the unit heat value and obtaining a heat value per unit time, and temperature estimating means for successively adding the heat value per unit time with a correcting operation in consideration of a radiation with the passage of time to obtain an added value and for estimating a heat generation temperature of the electric motor based on the added value.
According to the invention, the unit heat value for one pass unit of the carriage is calculated by the unit calorific value acquiring means based on the consumed current and the driving time of the electric motor, and the unit heat value is successively added to obtain the heat value per unit time by the heat value acquiring means. Then, the temperature estimating means successively adds the heat value per unit time with the correcting operation in consideration of the radiation with the passage of time to obtain an added value, and furthermore, the heat generation temperature of the electric motor is estimated based on the added value. Accordingly, it is possible to estimate the heat generation temperature of the electric motor comparatively accurately. For example, a pause is taken at the interval of the driving operation of the electric motor so that the heat generating limitation control for reducing the effective current value can be carried out suitably.
(14) In order to achieve the fourth object, the invention is directed to a serial type recording apparatus in which a carriage having a recording head is reciprocated in a main scanning direction, thereby carrying out recording over a recording medium by the recording head, comprising an electric motor to be driven for reciprocating the carriage in the main scanning direction, unit heat value acquiring means for calculating a unit heat value per pass of the carriage based on a consumed current and a driving time of the electric motor, heat value acquiring means for successively adding the unit heat value and obtaining a heat value per unit time, and heat generation abnormality deciding means for deciding a heat generation abnormality when an added value obtained by successively adding the heat value per unit time with a correcting operation in consideration of a radiation with the passage of time exceeds a predetermined threshold.
According to the invention, the unit heat value for one pass unit of the carriage is calculated by the unit heat value acquiring means based on the consumed current and the driving time of the electric motor, and the unit heat value is successively added to obtain the heat value per unit time by the heat value acquiring means. Then, the heat generation abnormality deciding means decides a heat generation abnormality when an added value obtained by successively adding the heat value per unit time with the correcting operation in consideration of the radiation with the passage of time exceeds a predetermined threshold. Accordingly, it is possible to decide the heat generation abnormality of the electric motor comparatively accurately.
(15) According to the invention, in the recording apparatus in accordance with any of the inventions (2) to (14) the calculation for obtaining the value related to the heat storage amount or the correcting operation uses a radiation factor determined by a time constant of a radiation system with the passage of time.
According to the invention, in addition to the functions of the invention according to any of claims 2 to 14, the operation for calculating the value related to the heat storage amount or the correcting operation uses the radiation factor determined from the time constant of the radiation system with the passage of time. Therefore, the influence of the radiation is considered accurately to obtain the heat value.
(16) In the invention, the recording apparatus described in (15) further comprises deciding means for deciding whether the radiation system is a heat generation system for carrying out a radiation with heat generation and a radiation system for carrying out the radiation without the heat generation, a radiation factor corresponding to the system decided by the deciding means being selected to carry out the correcting operation.
According to the invention, in addition to the function of the invention (15), the deciding means decides whether the radiation system is the heat radiation system for carrying out a radiation with the heat generation or the radiation system for carrying out the radiation without the heat generation. Then, the radiation factor corresponding to the system decided by the deciding means is selected to carry out the correcting operation.
(17) In the invention, in the recording apparatus described in (16), the deciding means counts the number of movements of a carriage to be driven by the electric motor and decides a system for determining the radiation factor based on the number of the movements of the carriage thus counted.
According to the invention, in addition to the function of the invention (16), the deciding means counts the number of the movements of the carriage to be driven by the electric motor and decides the system for determining the radiation factor based on the number of the movements of the carriage thus counted. Accordingly, it is possible to decide the radiation system comparatively easily.
(18) In the invention, in the recording apparatus according to any of (2) to (17), there is provided a memory for storing an added value obtained immediately before a power supply is turned OFF, the added value stored in the memory when the power supply is turned ON being read and used as an initial value.
According to the invention, a last added value is stored in the memory when the power supply is turned OFF and the added value stored in the memory is read and is used as an initial value when the power supply is turned ON. Accordingly, even if the power supply is turned OFF in such a state that the electric motor generates heat comparatively and the power supply is immediately turned ON, the added value is used as the initial value when the power supply is turned OFF. Therefore, it is possible to prevent the overheat generation state of the electric motor from being eliminated.